There have been machine tools, for example, automatic lathes for supplying a longitudinal bar material through a through hole of a main shaft from a back part of the main shaft, feeding the bar material in a main shaft axis line direction by each predetermined length, and continuously performing processing such as turning and grinding, or for supplying a material for one product to the main shaft from a front part of the main shaft by a robot, and the like.
Among these, in the former machine tool, the tip end of the bar machine tool is projected from the tip end of the main shaft by a predetermined length, a tool rest or head stock is moved to perform predetermined processing, and thereafter a product is cut from the bar machine tool with tools such as a cut-off tool. Subsequently, the cut/separated product is recovered by a product recovery apparatus.
FIG. 16 shows a related art of the former machine tool, and is a schematic view of a main part of an automatic lathe including a product recovery apparatus.
In FIG. 16, a head stock 2 is disposed on a base 4 of the automatic lathe, and a main shaft 1 is rotatably supported on the head stock 2. The head stock 2 freely moves forwards and backwards along a screw shaft 3 on the base 4 in a Z-direction which is the same direction as that of an axis line of the main shaft 1.
A support member 7 for supporting a guide bush 6 is disposed before the head stock 2 (on the left side of FIG. 16), and the tip end of a bar material B supplied through the through hole of the main shaft 1 is supported by the guide bush 6. A tool rest such as a comb teeth-shaped tool rest for holding a plurality of tools T is disposed in the vicinity of the support member 7, so that the tools T such as a cutting tool for performing predetermined turning and a cut-off tool for performing cutting-off can be disposed in a processing position before the guide bush 6.
In the automatic lathe shown in FIG. 16, the head stock 2 can move by the screw shaft 3. Moreover, the tip end of the bar material B is projected from the guide bush 6, the head stock 2 is fed in the Z-direction, and the tool T is fed in an X-direction, so that the tip end of the bar material B is processed. After the processing ends, in a vicinity position before the guide bush 6, the bar material B is cut off by the tool T such as the cut-off tool, and a product W is separated from the bar material B. During the processing of the bar material B by the tool T, a coolant supplied from a coolant nozzle 8 is spouted toward the tool T and bar material B.
A product recovery apparatus 20 is disposed before the head stock 2. Moreover, the apparatus 20 includes: a cylinder 21 including a stretchable piston rod 21a; a chute 22 for product recovery which moves forwards and backwards between a position right under a cover 9 disposed below the guide bush 6 and a retreat position far from the support member 7; a receiver box 25 for receiving/recovering the product W via the chute 22; and a funnel-shaped member 24 disposed between the receiver box 25 and chute 22. The chute 22 is attached to the tip end of the piston rod 21a of the cylinder 21, and reciprocates/moves between the position right under the cover 9 and the retreat position by driving the cylinder 21.
In the product recovery apparatus 20 constituted as described above, the cylinder 21 is driven to position the chute 22 right under the cover 9 immediately before the product W is cut off. The chute 22 receives the cut off and falling product W. As shown in FIG. 16, since the chute 22 is inclined toward the receiver box 25, the product slides down along the chute 22, and is transferred to the funnel-shaped member 24. Subsequently, the product W drops and is recovered into the receiver box 25 disposed under the funnel-shaped member 24.
Additionally, the product recovery apparatus 20 shown in FIG. 16 has the following problem.
That is, since the coolant is continuously supplied from the coolant nozzle 8 even at a cut-off time, the coolant is recovered together with the product W into the receiver box 25 from the chute 22 via the funnel-shaped member 24. Moreover, since the chute 22 and funnel-shaped member 24 are disposed in a processing chamber of the automatic lathe in an exposed state, a large amount of cut wastes generated during the processing enters the receiver box 25 together with the coolant, and the cut wastes adhere to the chute 22 and funnel-shaped member 24. Moreover, the products W are thereby mixed/recovered together with the coolant and cut wastes in the receiver box 25, and there is a disadvantage that the receiver box 25 soon becomes full. Furthermore, the product W is entangled with or caught by the cut wastes in the chute 22 and funnel-shaped member 24, the product W is mixed/recovered together with the coolant and cut wastes in the receiver box 25, and this causes a disadvantage that it takes a lot of trouble to recover the product W separately from the cut wastes.
Furthermore, to cut/form micro components such as clock components, the product W flowing together with the coolant into the receiver box 25 sometimes flows outside the receiver box 25 together with the coolant running over the receiver box 25, and there is a possibility that recovery rate of the product W drops.
To solve the problem, for example, in Japanese Patent Application Laid-Open No. 1997-94704, a product recovery apparatus is disclosed which includes a tube also having a guide function of preventing the component from vibrating at a cut-off time and which uses the tube to recover the cut-off component by air suction.
FIG. 17 shows a schematic view of the product recovery apparatus described in the Japanese Patent Application Laid-Open No. 1997-94704.
It is to be noted that mechanisms such as the head stock, main shaft, tool, disposed in the automatic lathe, for processing the bar material B are the same as those of the automatic lathe shown in FIG. 16, and therefore are denoted with the same reference numerals, and detailed description thereof is omitted.
A product recovery apparatus 30 includes: a guide tube 31 for guiding the bar material B at the cut-off time so that the tip end of the material does not vibrate; an air tube 32 connected to the guide tube 31; a vacuum pump 36 for performing air suction; and a receiver box 35 which receives the recovered product W.
The vacuum pump 36 is connected to the air tube 32 via a branch pipe 36a branched halfway from the air tube 32. The guide tube 31 is formed of a cylindrical member of a metal, and supported on the same axis line as that of the main shaft 1 by a support member 33 fixed to a table 5 of the automatic lathe. Moreover, the tip end of the tube 31 is positioned so that a part of the product W is inserted into the tip end of the guide tube 31 at the cut-off time of the product W from the bar material B.
Moreover, opening/closing means for closing an opening on an outlet side of the air tube 32 is disposed on a product outlet side of the air tube 32, that is, on a receiver box 35 side so as to prevent air from being sucked on the product outlet side of the air tube 32, when the vacuum pump 36 is driven to perform the air suction.
The opening/closing means includes a cylinder 38, and an opening/closing member 39 attached to the tip end of a stretchable piston rod 38a of the cylinder 38. To recover the product W by the air suction, the cylinder 38 is driven to close the opening of the air tube 32 on the outlet side, and the opening/closing member 39 is opened after the suction of the product W, so that the product W is allowed to drop, and recovered in the receiver box 35.
According to the product recovery apparatus 30, since the product W cut off by the guide tube 31 is recovered, the amount of the coolant and cut wastes recovered together with the product W in the receiver box 35 becomes remarkably small. Moreover, the product recovery apparatus 30 can be disposed apart from a processed portion or outside the processing chamber, and therefore there is an advantage that influence of the cut wastes flied during the processing is not easily exerted.
However, in the product recovery apparatus described in the Japanese Patent Application Laid-Open No. 1997-94704, the branch tube 36a is branched halfway from the air tube 32 and connected to the vacuum pump 36, the cut wastes and coolant sucked from the guide tube 31 are therefore sucked into the vacuum pump 36, and there is a problem that an operation defect of the vacuum pump 36 is possibly caused. Moreover, with the product recovery apparatus 30 disposed outside the processing chamber, there is a problem that the automatic lathe is enlarged.
Furthermore, the product W recovered by the air suction collides against the opening/closing member 39 at high speed, and therefore there is a problem that the product W is possibly scratched and deformed. Moreover, in the structure, there is a gap between the opening/closing means and receiver box 35, therefore the product W which has forcefully jumped into the receiver box 35 jumps out of the receiver box 35, and there is a problem that the recovery rate of products drops. Additionally, a mechanism for opening/closing the opening/closing member 39 is complicated, and there is a problem that an apparatus price rises.
It is to be noted that in addition to the above-described Japanese Patent Application Laid-Open No. 1997-94704, a product recovery apparatus described in Japanese Patent Application Laid-Open Nos. 1985-76901 and 19821-26947 is known. However, either constitution is complicated, the apparatus price is high, and it is difficult to dispose the apparatus in the processing chamber filled with the cut wastes and coolant mist.
Moreover, there is a mode for grasping and conveying the product W by a chuck in the apparatuses described in the above-described publications, but this apparatus has a problem that it is difficult to recover the product depending on the shape of the product W.
On the other hand, in the latter machine tool for supplying the material for one product to the main shaft to process the material by relative movement with the tool, discharging the processed product, and again supplying the next material to repeat the processing, in order to supply the material and discharge the product in a short time, it is general to dispose a plurality of grasp means for supplying the material and discharging the product on the tip end of a robot for conveyance (not shown) and to supply the material and discharge the product from a position before the main shaft.
However, this method has the following problem. It is necessary to dispose at least two or more grasp means separately for the material supply and for the product discharge on the tip end of the robot for conveyance, and therefore a conveyable weight of the robot for conveyance increases. Moreover, before the main shaft, the robot for conveyance is positioned in at least two positions, and it is necessary to complicate the control and to secure a space around the main shaft. Furthermore, it is necessary to reduce a conveyance speed of the robot for conveyance, and as a result a rise of equipment cost and decrease of productivity are caused.
The present invention has been developed in consideration of the above-described problems, and an object thereof is to provide a product recovery apparatus and a product recovery method which can be applied to various types of products and which can be disposed in the vicinity of a portion to be processed or in a processing chamber filled with cut wastes and mist of the coolant and by which the cut wastes are prevented from being mixed into a receiver box and recovered products are prevented from being damaged and which save space and have high recovery rate of products.